Solutions are not obvious. It really is hard to think of any path forward from this point.
A lot of the problem started with public schools which were taken over by leftists as part of the “long march through the institutions” when they realized violent revolution was just not going to happen in the west.
Taking away their right to vote won’t work...they are actively working to end elections. Besides, who decides who gets to keep or lose one’s voting right
S?
When they lose the civil war they lose the right to vote. It's not who decides. It will be decided for them by the winners of the war like always. They might even lose the right to own property if they aren't careful. How long these rights are lost may depend on background checks done to find out how much of a villain they were/are.